1. Field of the Invention
This invention relates to securing devices of the sort which may be used in fixing furniture panels together. More particularly, but not exclusively, it relates to the type of securing device which comprises a fastening element which may be used in conjunction with a tightening member of the rotating cam lock type.
2. Description of the Prior Art
Securing devices are known which comprise a fastening element in the form of a pin and a tightening member in the form of a rotating cam lock. The pin is inserted in a first panel to a predetermined depth and fixed. In this position its head and a portion of its body protrude from the panel. The protruding parts of the pin are passed into a bore in a second panel, which is to be joined to the first, where the head of the pin engages inside the cam lock positioned in a recess in the second panel. The cam lock has a camming surface which acts to draw the pin inwardly as the lock is turned, thus drawing the two panels together.
The pins used in this type of securing device are generally made from turned steel and typically have a central body portion of relatively large diameter and a threaded end portion of smaller diameter for insertion in the first panel. The change in diameter between the body portion and threaded end portion acts as a stop to limit insertion of the pin in the first panel to the required predetermined depth. At the opposite end of the pin is a head and narrower neck portion connecting the head to the body portion, the head and neck being shaped to co-operate with the camming surface of the rotating cam lock. An example of this type of prior art pin is shown in FIG. 1.
These steel pins are relatively costly to manufacture, requiring turning to provide the different diameter portions and the screw thread. A cheaper pin may be manufactured from die-cast Mazak, and the use of this material has several advantages in addition to reduced cost. For instance, the tolerances achievable in die-casting are much smaller than those which can be attained in turning steel pins so that it is possible to manufacture die-cast pins which have a much better fit with the cam lock. Features may also be incorporated in the pin design which cannot be achieved by turning.
An example of a feature which can be included if the pins are die-cast is a flared skirt to act as the stop which limits insertion of the pin in a panel to a predetermined depth. An example of this type of prior art pin is shown in FIG. 2. Using a skirt in this way removes the need for a large diameter body portion of the pin, so that the bore in the second panel through which the protruding body portion of the pin passes can also be reduced in size, making easier the preparation of the panels prior to fixing.
However, the use of the flared skirt does give rise to some disadvantages. For instance, in order for the panels to lie in full contact with one another it is necessary to counter-sink the bore in the second panel to accommodate the skirt of the pin, thus necessitating a further step in the preparation of the panels. Unless the countersinking is very accurate it is possible that the edge of the skirt may protrude slightly, giving rise to a gap between the panels when
they are fixed.